Rework TIMESTAMP ARG to (hopefully) work; manually set PATH to includ…

…e pipx installs

images/python-base/Dockerfile

@@ -1,10 +1,14 @@
-# e.g., "3.10"
+# > An ARG declared before a FROM is outside of a build stage, so it can't be used in any instruction after a FROM
+# https://docs.docker.com/engine/reference/builder/#understand-how-arg-and-from-interact
+
+# Specify "base" Python image e.g., "3.10"
 ARG PYTHON_VERSION
-# e.g., 2024.01.17.15.09.31
-ARG TIMESTAMP
 
 FROM python:${PYTHON_VERSION}-slim as python-base-BASE
 
+# For tracking deployed images later e.g., 2024.01.17.15.09.31
+ARG TIMESTAMP
+
     # Python
 ENV PYTHONUNBUFFERED=1 \
     # prevents python creating .pyc files
@@ -18,19 +22,16 @@ ENV PYTHONUNBUFFERED=1 \
     # do not ask any interactive question
     POETRY_NO_INTERACTION=1 \
     # never create virtual environment automaticly, only use env prepared by us
-    POETRY_VIRTUALENVS_CREATE=false
+    POETRY_VIRTUALENVS_CREATE=false \
+    # Update PATH to include pipx defautl
+    PATH="/root/.local/bin:${PATH}"
 
 # Install pipx. pipx installs Python CLI programs in an isolated environment
 # in addition it makes the CLI entry points available on $PATH
-RUN pip install --upgrade pipx && \
-    pipx ensurepath
+RUN pip install --upgrade pipx
 
 # Install poetry via pipx
 # https://python-poetry.org/docs/#installing-with-pipx
-#
-# NOTE: this will emit "'/root/.local/bin' is not on your PATH environment variable."
-#       This is true at install time but at runtime a new shell will be started that
-#       has that fixed per `pipx ensurepath` above
 RUN pipx install poetry
 
 # Leave a note behind so we can always quickly determine our original image